Annuloplasty sizers for minimally invasive procedures

ABSTRACT

A sizing plate for sizing a native valve annulus in a patient&#39;s heart for either valve replacement or repair during a minimally invasive surgical procedure is shown and described. The sizing plate is generally shaped such that it corresponds to the shape of the native valve annulus. Additionally, a thickness of the sizing plate is such that it can be inserted through a space between the ribs of the patient during the procedure. The sizing plate includes two keyways extending though the plate separated by a bridge. The keyways are sized and shaped such that they are adapted to be engaged by a minimally invasive surgical tool such as a laparoscopic grasper. The keyways in conjunction with the bridge facilitate manipulation of the sizing plate by the grasper from an external location.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C §119 of U.S.Provisional Application No. 61/163,732, filed on Mar. 26, 2009, entitled“Annuloplasty Sizers for Minimally Invasive Procedures,” which is hereinincorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

The present invention relates to devices, kits, and methods for sizingthe annulus of an anatomical structure. More particularly, the presentinvention is related to sizing plates for use in minimally invasivesurgical procedures to repair or replace a diseased native valve.

BACKGROUND

A heart valve can become defective or damaged, such as resulting fromcongenital malformation, disease, or aging. When the valve becomesdefective or damaged, the leaflets may not function properly. One commonproblem associated with a degenerating heart valve is an enlargement ofthe valve annulus (e.g., dilation). Other problems that may result invalve dysfunction are chordal elongation and lesions developing on oneor more of the leaflets. Adverse clinical symptoms, such as chest pain,cardiac arrhythmias, dyspnea, may manifest in response to valve prolapseor regurgitation. As a result, surgical correction, either by valverepair procedures or by valve replacement, may be required.

Surgical reconstruction or repair procedures may include plication,chordal shortening, or chordal replacement. Another common repairprocedure relates to remodeling of the valve annulus (e.g.,annuloplasty), which may be accomplished by implantation of a prostheticring to help stabilize the annulus and to correct or help preventvalvular insufficiency which may result from defect or dysfunction ofthe valve annulus. Properly sizing and implanting the annuloplasty ringmay substantially restore the valve annulus restored to its normal,undilated, circumference. In other situations, the valve can bereplaced. During valve replacement procedures, the valve annulus issized so as to select an appropriately sized replacement valve.

SUMMARY

The present invention relates to devices, kits, and methods for sizingthe annulus of an anatomical structure. More particularly, the presentinvention is related to sizing plates for use in minimally invasivesurgical procedures to repair or replace a diseased native valve.

Example 1 is a sizing plate for sizing a native valve annulus in apatient's during a minimally invasive valve replacement repair orprocedure. The sizing plate includes an upper surface and a lowersurface defining a thickness of the sizing plate between the upper andlower surfaces; first and second keyways extending through the sizingplate from the upper planar surface to the lower planar surface of thesizing plate; and a bridge member between the first and second keywaysconfigured to be engaged by a laparoscopic grasping tool.

Example 2 is a sizing plate according to Example 1, wherein the sizingplate is generally D-shaped.

Example 3 is a sizing plate according to any one of Examples 1-2,wherein the sizing plate has a shape generally corresponding to a shapeof the anterior leaflet of the native mitral valve.

Example 4 is a sizing plate according to any one of Examples 1-3,wherein the bridge member comprises a bar coupled to the sizing plate.

Example 5 is a sizing plate according to any one of Examples 1-4,wherein at least a portion of the sizing plate is radiopaque.

Example 6 is a sizing plate according to any one of Examples 1-5,wherein the first and second keyways have a trapezoidal shape.

Example 7 is a sizing plate according to any one of Examples 1-6,wherein the sizing plate is generally D-shaped having a major dimensionand a minor dimension, and wherein the bridge is oriented substantiallyparallel to the major dimension.

Example 8 is a sizing plate according to any one of Examples 1-7,further comprising an aperture extending through the upper and lowersurfaces disposed near a lower edge of the sizing plate.

Example 9 is a sizing plate according to any one of Examples 1-8,wherein the thickness of the sizing plate defined between the upperplanar surface and the lower planar surface is such that the sizingplate is adapted to be inserted through a space between a patient's ribswhen the sizing plate is oriented on an edge.

Example 10 is a kit for sizing a native valve annulus in a patient'sheart during a minimally invasive valve replacement or repair procedure.The kit according to Example 10 includes: a plurality of sizing platesof differing size for sizing the native valve annulus, each sizing platehaving a shape generally corresponding to a shape of the anteriorleaflet of the native mitral valve and having a major dimension and aminor dimension, wherein at least one of the major dimension and theminor dimension varies among the plurality of sizing plates. Each sizingplate further includes: an upper planar surface and a lower planarsurface defining a thickness of the sizing plate between the upper andlower planar surfaces; first and second keyways extending through thesizing plate from the upper planar surface to the lower planar surfaceof the sizing plate; and a bridge between the first and second keywaysconfigured to be engaged by a laprascopic grasping tool.

Example 11 is a kit according to Example 10, wherein the bridge of eachsizing plate is oriented substantially parallel to the major dimension

Example 12 is a kit according to any one of Examples 10-11, furtherincluding a grasping tool.

Example 13 is a kit according to any one of Examples 10-12, wherein eachsizing plate is generally D-shaped.

Example 14 is a kit according to any one of Examples 10-13, wherein thefirst and second keyways of each sizing plate have a trapezoidal shape.

Example 15 is a kit according to any one of Examples 10-14, wherein eachof the sizing plates further includes at least one aperture disposednear a lower edge of the sizing plate.

Example 16 is a kit according to any one of Examples 10-15, wherein thethickness of each of the sizing plates is such that the sizing plate isadapted to be inserted through a space between a patient's ribs when thesizing plate is oriented on an edge.

Example 17 is a method of sizing a native valve annulus during aminimally invasive surgical procedure. The method according to Example17 includes the steps of:

-   -   a) creating a surgical access port in an intercostals space in a        patient's body;    -   b) exposing a native mitral valve annulus;    -   c) inserting a first sizing plate through the surgical access        port, the sizing plate including: an upper surface and a lower        surface defining a thickness of the sizing plate; first and        second keyways extending through the sizing plate from the upper        planar surface to the lower planar surface of the sizing plate;        and a bridge member between the first and second keyways        configured to be engaged by a laparoscopic grasping tool;    -   d) engaging a the bridge of the sizing plate using a        laparoscopic grasping tool inserted through the surgical access        port;    -   e) positioning the sizing plate in the valve annulus;    -   f) comparing the major and minor dimensions and the shape of the        sizing plate to a major and a minor dimension and shape of an        anterior leaflet of the mitral valve; and    -   g) determining the major and minor dimensions and shape of the        anterior leaflet of the mitral vale.

Example 18 is a method according to Example 17, further including thesteps of: removing the first sizing plate from the patient's body;inserting a second sizing plate through the surgical access port, thesecond sizing plate comprising a major dimension and a minor dimensionand a shape generally corresponding to the shape of the anterior leafletof the mitral valve; an upper planar surface and a lower planar surfacedefining a thickness of the sizing plate; and a first keyway and asecond keyway to facilitate engagement of a grasping tool with thesizing plate, the first and second keyways generally centered on thesizing plate and extending through the sizing plate from the upperplanar surface to the lower planar surface of the sizing plate; andrepeating steps c)-g).

Example 19 is a method according to any one of Examples 17-18, furtherincluding the step of temporarily suspending the sizing plate throughthe access port.

Example 20 is a method according to any one of Examples 17-19, furtherincluding the step of orienting the first sizing plate on an edge wheninserting the first sizing plate through the surgical access port.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a sizing plate according to an embodimentof the present invention.

FIG. 2 is a schematic view of a sizing plate according to anotherembodiment of the present invention.

FIG. 3 is a schematic view of a minimally invasive surgical tool engagedwith the sizing plate as shown in FIG. 1 according to one embodiment ofthe present invention.

FIG. 4 is a schematic view of a set of sizing plates according to oneembodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of a sizing plate 10 according to variousembodiments of the present invention. The sizing plate 10 can be used todetermine the size of an annulus of an anatomical structure within apatient's body during a minimally invasive surgical procedure. In theillustrated embodiments, the sizing plate 10 can be used to determinethe size of an anterior leaflet of a patient's native mitral valveduring a minimally invasive surgical procedure to repair or replace thenative valve. Accordingly, the sizing plate 10 generally has a size andshape corresponding to that of the anterior leaflet of the native mitralvalve to be repaired. Upon determination of the appropriately sizedsizing plate 10, the clinician can then select a correspondingannuloplasty prosthesis, which is then secured to the valve annuls toreshape the annulus to improve coaptation of the anterior and posteriorvalve leaflets. In some embodiments, the sizing plate 10 includes asubstantially straight lower edge 11, an arcuate upper edge 12, andfirst and second side edges 13 a and 13 b extending between thesubstantially straight lower edge 11 and the arcuate upper edge 12. Inthe illustrated embodiment of FIG. 1, the sizing plate 10 is configuredfor use in a mitral valve repair procedure, and therefore has thecharacteristic “D”-shape of a native mitral valve annulus, withorthogonal major and minor dimensions D and d, respectively. In variousother embodiments, the sizing plate 10 has a size and shape generallycorresponding to the annulus of another cardiac valve, e.g., the aorticvalve.

The sizing plate 10 is sized such that it can be inserted through aminimally invasive surgical access port formed in a patient's body.According to various embodiments, the sizing plate 10 is generallyplanar and includes an upper planar surface 14 and a lower planarsurface 16. In some embodiments, a thickness of the sizing plate 10defined between the upper and lower planar surfaces 14 and 16facilitates insertion of the sizing plate 10 on its side through anarrow surgical access port. For example, in some embodiments, athickness of the sizing plate 10 is such that it can be inserted on itsside through a space between a patient's ribs. In one embodiment, thesizing plate 10 has a thickness of about 0.125 inches (0.317 cm). Inother embodiments, the overall outer size and shape of the sizing plate10 is small enough such that the sizing plate 10 need not be insertedthough a minimally invasive surgical access port on its side, but rathercan be inserted face-down through the surgical access port.

As shown in FIG. 1, the sizing plate 10 includes a first keyway 20 a anda second keyway 20 b extending through the sizing plate 10 from theupper surface 14 to the lower surface 16. The two keyways 20 a, 20 b aregenerally centered in the sizing plate 10 and are separated from oneanother by a bridge 24. In one embodiment, as shown in FIG. 1, thekeyways 20 a, 20 b are formed in the sizing plate 10 as mirror images ofone another. The keyways 20 a, 20 b and the bridge 24 facilitateengagement of a surgical tool with the sizing plate 10, as will bedescribed in further detail below.

In the illustrated embodiment, the size and shape of the keyways 20 a,20 b facilitate engagement of the sizing plate by a minimally invasivesurgical tool, e.g., a standard laparascopic grasper. Additionally, thedimensions of the keyways 20 a, 20 b are selected so as to limitmovement of the surgical tool within the keyways 20 a, 20 b, once thesurgical tool is engaged with the sizing plate 10.

As further shown, each keyway 20 a, 20 b has a generally trapezoidalshape. Thus, the shape of the keyway 20 a is defined by substantiallyparallel first and second sides 28 a, 32 a, and lateral sides 29 a, 33 aextending between the first and second sides 28 a, 32 a. Additionally,the keyway 20 b has substantially parallel first and second sides 28 b,32 b and lateral sides 29 b, 33 b therebetween. In the illustratedembodiment, the sides 28 a, 28 b, 32 a, and 32 b of the keyways 20 a, 20b are oriented substantially parallel to the major dimension D of thesizing plate 10, and the keyways 20 a, 20 b are generally laterallycentered on the sizing plate 10.

As shown, the first sides 28 a, 28 b of the keyways 20 a, 20 b aregenerally narrower than the second sides 32 a, 32 b, respectively, so asto define the illustrated trapezoidal shape of the keyways 20 a, 20 b.Additionally, the bridge 24 separates the first sides 28 a, 32 a of thekeyways 20 a, 20 b, and provides a structure which can be gripped by aminimally invasive grasping tool. In one embodiment, the bridge 24 isintegrally formed with the sizing plate 10. In another embodiment, thebridge 24 is a separate member that is coupled to the sizing plate 10during the fabrication of the sizing plate 10. As can be seen in FIG. 1,the bridge 24 has a length L corresponding to the length of the firstsides 28 a, 32 a of the keyways 20 a, 20 b. As discussed in greaterdetail below, the dimensions of the keyways 20 a, 20 b facilitate andguide insertion of the working ends of a surgical tool into secureengagement with the sizing plate 10 while the bridge 24 is gripped bythe surgical tool.

According to some embodiments, as shown in FIG. 1, the sizing plate 10also includes at least one aperture 36 in addition to the keyways 20 a,20 b. Like the keyways 20 a, 20 b, the aperture 36 extends through thesizing plate from the upper surface 14 to the lower surface 16. Theaperture 36 can be provided at any location on the sizing plate 10. Inone embodiment, the aperture 36 is located at or near a bottom side edge38 of the sizing plate 10. In another embodiment, two apertures areprovided at or near opposite bottom side edges of the sizing plate 10(shown in FIG. 2 described below). According to various embodiments, asuture can be threaded through the aperture 36 such that the sizingplate 10 can be lowered and/or suspended through a surgical access portformed in the patient's body.

FIG. 2 is a schematic view of a sizing plate 100 according to anotherembodiment of the present invention. As described above, the sizingplate 100 is configured for use in a mitral valve repair procedure, andtherefore has the characteristic “D”-shape of an anterior leaflet of anative mitral valve, with orthogonal major and minor dimensions D and d,respectively. In various other embodiments, the sizing plate 100 has asize and shape generally corresponding to the annulus of another cardiacvalve, e.g., the aortic valve. According to various embodiments, thesizing plate 100 includes a substantially straight lower edge 111, anarcuate upper edge 112, and first and second side edges 113 a and 113 bextending between the substantially straight lower edge 111 and thearcuate upper edge 112. According to some embodiments, the sizing plate100 can also include at least one notch 114 formed in one of the edges(111, 112, 113 a, 113 b) of the sizing plate 100. In one embodiment, asshown in FIG. 2, the sizing plate 100 includes two notches 114, eachnotch 114 formed in each of the first and second side edges 113 a, 113b. The notches 114 can be used by the clinician to orient and align thesizing plate 100 with the native valve annulus.

The sizing plate 100 is sized such that it can be inserted through aminimally invasive surgical access port formed in a patient's body.According to various embodiments, the sizing plate 100 is generallyplanar and includes an upper planar surface 115 and a lower planarsurface 116. In some embodiments, a thickness of the sizing plate 100defined between the upper and lower planar surfaces 115 and 116facilitates insertion of the sizing plate 100 on its side through anarrow surgical access port. For example, in some embodiments, athickness of the sizing plate 100 is such that it can be inserted on itsside through a space between a patient's ribs. In one embodiment, thesizing plate 100 has a thickness of about 0.125 inches (0.317 cm). Inother embodiments, the overall outer size and shape of the sizing plate100 is small enough such that the sizing plate 100 need not be insertedthough a minimally invasive surgical access port on its side, but rathercan be inserted face-down through the surgical access port.

As shown in FIG. 2, the sizing plate 100 includes a first keyway 120 aand a second keyway 120 b extending through the sizing plate 100 fromthe upper surface 115 to the lower surface 116. The two keyways 120 a,120 b are generally centered in the sizing plate 100 and are separatedfrom one another by a bridge 124. The keyways 120 a, 120 b and thebridge 124 facilitate engagement of a surgical tool with the sizingplate 100, as will be described in further detail below.

As described above, the size and shape of the keyways 120 a, 120 bfacilitate engagement of the sizing plate by a minimally invasivesurgical tool, e.g., a standard laparoscopic grasper. Additionally, thedimensions of the keyways 120 a, 120 b are selected so as to limitmovement of the surgical tool within the keyways 120 a, 120 b, once thesurgical tool is engaged with the sizing plate 100.

As further shown, each keyway 120 a, 120 b has a generally trapezoidalshape. Thus, the shape of the keyway 120 a is defined by substantiallyparallel first and second sides 128 a, 132 a, and lateral sides 129 a,133 a extending between the first and second sides 128 a, 132 a.Additionally, the keyway 120 b has substantially parallel first andsecond sides 128 b, 132 b and lateral sides 129 b, 133 b therebetween.In the illustrated embodiment, the sides 128 a, 128 b, 132 a, and 132 bof the keyways 120 a, 120 b are oriented substantially parallel to themajor dimension D of the sizing plate 100, and the keyways 120 a, 120 bare generally laterally centered on the sizing plate 100.

As shown, the first sides 128 a, 128 b of the keyways 120 a, 120 b aregenerally narrower than the second sides 132 a, 132 b, respectively, soas to define the illustrated trapezoidal shape of the keyways 120 a, 120b. Additionally, the bridge 124 separates the first sides 128 a, 128 bof the keyways 120 a, 120 b, and provides a structure which can begripped by a minimally invasive grasping tool.

In some embodiments, as shown in FIG. 2, the bridge 124 is a separatemember that is coupled to the sizing plate 100. For example, in oneembodiment, the bridge 124 is a bar or rod that is insert-molded intothe sizing plate 100, as will be described in more detail below. The baror rod used to fabricate the bridge 124 can be made from a metal, metalalloy or other suitable biocompatible material. In one example, the baror rod used to form the bridge 124 is a titanium bar or rod. The rod orbar used to form the bridge 124 can have a variety of cross-sectionsincluding round, elliptical, square, rectangular or another polygonalcross-section. In one embodiment, the rod or bar has a rectangularcross-section to facilitate an engagement of the bridge 124 by agrasping tool. The bridge 124 formed by the bar or rod has a length Lcorresponding to the length of the first sides 128 a, 128 b of thekeyways 120 a, 120 b.

According to some embodiments, as shown in FIG. 2, the sizing plate 100includes at least two apertures 136 in addition to the keyways 120 a,120 b. Like the keyways 120 a, 120 b, the apertures 136 extends throughthe sizing plate 100 from the upper surface 115 to the lower surface116. The apertures 136 can be provided at any location on the sizingplate 100. In one embodiment, the apertures 136 are located at or near abottom side edge 138 of the sizing plate 100. According to variousembodiments, a suture can be threaded through either aperture 136 suchthat the sizing plate 100 can be lowered and/or suspended through asurgical access port formed in the patient's body.

The sizing plates 10 and 100, described above with reference to FIGS. 1and 2, can be fabricated from a variety of biocompatible materials.According to some embodiments, the sizing plates 10 and 100 can befabricated from any lightweight metal or metal alloy. For example, inone embodiment, the sizing plates 10 and 100 can be fabricated fromtitanium or a titanium alloy. Exemplary metal fabrication techniquesthat can be used to fabricate the sizing plates 10 and 100 includemachining, stamping, and die-punching.

In other embodiments, the sizing plates 10 and 100 can be fabricatedfrom a polymeric or plastic material. In one embodiment, the sizingplates 10 and 100 can be fabricated from a thermoplastic material.Exemplary thermoplastic materials suitable for use in the human body arewell known in the art. In one example, the sizing plates 10 and 100 canbe fabricated from a polyetherimide such as ULTEM®. In other examplespolytetrafluoroethylene (PTFE or TEFLON®) or polyether ether ketone(PEEK) can be used to fabricate the sizing plates 10 and 100. Theplastic material can be formed into the sizing plates 10 and 100 using avariety of plastic fabrication techniques including injection molding.In one embodiment, the sizing plates 10 and 100 are injection moldedfrom a thermoplastic material. In a separate step, before thethermoplastic is cured, the bridge 124, as described with reference toFIG. 2, can be insert-molded into the sizing plate 100. Thus, the bridge124 is not limited to being fabricated from the same material as thesizing plates 10 and 100, but can be selected from a different materialand even a different class of material. For example, in someembodiments, the bridge 124 can be a rod or bar made from a metal ormetal alloy. In another embodiment, the bridge 124 can be radiopaque.

In some embodiments, the sizing plates 10 and 100 can be fabricated suchthat at least a portion of the sizing plates 10 and 100 is radiopaque.In one embodiment, an entire sizing plate 10 or 100 is fabricated suchthat it is radiopaque. The sizing plates 10 and 100 can be maderadiopaque by selecting a radiopaque material for fabrication of thesizing plate 10, 100 or by incorporating a radiopaque material into thematerial used to fabricate the sizing plate 10, 100. By fabricating thesizing plate 10, 100 such that at least a portion of the sizing plate10, 100 is radiopaque, enable the clinician to easily visualize thesizing plate 10, 100 during the sizing procedure under standardvisualization techniques including fluoroscopy and X-ray.

FIG. 3 is a schematic view of a minimally invasive surgical tool 40engaged with the sizing plate 10 shown in FIG. 1 according to variousembodiments of the present invention. The minimally invasive surgicaltool 40 is engaged with the sizing plate 10 to manipulate the sizingplate 10 within a valve annulus or other anatomical structure. Theminimally invasive surgical tool 40 facilitates manipulation of thesizing plate 10 from a location external the patient's body understandard visualization techniques. External manipulation of the sizingplate 10 may facilitate easier positioning and rotation of the sizingplate in the body which may result in a more accurate assessment of theshape and size of the valve annulus or other anatomical structure.

Various commercially available, minimally invasive surgical tools may beused with the sizing plate 10. In some embodiments, the minimallyinvasive surgical tool 40 is a laparoscopic grasper. Such laparoscopicgraspers are commercially available from a number of differentmanufactures and come in a variety of sizes. A grasper facilitates easymanipulation of the sizing plate from an external location. In oneembodiment, the minimally invasive surgical tool 40 is a 5 mm grasper.

As shown in FIG. 3, the working ends 44 a, 44 b of the surgical tool 40,such as, for example, a grasper are inserted into each of the keyways 20a, 20 b. As discussed above, the keyways 20 a, 20 b can be shaped andsized to accommodate insertion of the working ends 44 a, 44 b of variousminimally invasive surgical tools into engagement with the sizing plate10. The thickness of the sizing plate 10 and the length L and, in someembodiments, the cross-section of the bridge 24 also facilitateengagement of the surgical tool with the plate by providing a sufficientstructure for which the working ends 44 a, 44 b of the tool 40 cangrasp. Additionally, in one embodiment, a length L of the bridge 24provided between the two keyways 20 a, 20 b, can be slightly greaterthan a maximum width of each working end 44 a, 44 b of the surgical tool40 to be engaged with the sizing plate 10. For example, in oneembodiment, if the maximum width of each working end 44 a, 44 b of thegrasper is 5 mm, then the length L of the bridge 24 can be approximately6 mm.

FIG. 4 is a schematic view of a set 50 of sizing plates 10 according toan embodiment of the present invention. The set 50 includes one or moresizing plates 10 of increasing size having the same general shape.According to various embodiments, a maximum height of each plate(corresponding to the minor dimension d of the respective plate) rangesfrom about 0.657 to about 1.004 inches (from about 1.67 to about 2.55cm), and a maximum width of each plate (corresponding to the majordimension D of the respective plate) ranges from about 1.020 to about1.571 inches (from about 2.59 to about 4 cm). In some embodiments, eachplate 10 can include a size indicator 54 such as, for example, a numberlaser-etched, stamped embossed or pad-printed on a plate face 56indicating the size of the sizing plate 10. In one embodiment, the sizeindicator 54 can be stamped or pad-printed in radiopaque ink. Table 1indicates the maximum height and width corresponding to different platesizes. The maximum height and width are provided in inches (where 1inch=2.54 cm).

TABLE 1 Plate Max. Height Max. Width Size (Minor Dimension d) (MajorDimension D) 24 0.657 1.020 26 0.714 1.098 28 0.762 1.176 30 0.813 1.25632 0.862 1.334 34 0.910 1.412 36 0.960 1.493 38 1.004 1.571

Among a given set 50 of sizing plates 10, the size and shape of thekeyways 20 provided in each of the plates 10 remain the same such thatthey are able to engage with the same size of a minimally invasivesurgical tool 40. The set 50 of sizing plates 10 may be provided with orwithout a minimally invasive surgical grasper tool 40.

A method of using the sizing plate 10 according to the variousembodiments discussed above will now be described in reference toFIG. 1. During a minimally invasive surgical procedure to repair orreplace a diseased native valve such as the aortic or mitral valve, thesurgeon performing the procedure creates a surgical access port in anintercostal space in the patient's body. The surgeon may also create anaccess port via a mini-sternotomy whereby a piece of the sternum and itscorresponding rib are transected to create more space. A selected sizingplate 10 can then be inserted on its side through the access port. Insome embodiments, a suture can be inserted through the aperture 36provided in the plate and can be used to lower the sizing plate 10 onits side through the port. In some embodiments, the suture can be usedto temporarily suspend the sizing plate 10 through the access port atthe surgical site until the sizing plate 10 is ready for use. Next, thesurgeon retracts or excises the valve leaflets using standard techniquesto expose the valve annulus. A grasper or other minimally invasivesurgical tool 40 capable of engaging the sizing plate 10 is theninserted through the surgical access port and is engaged with the sizingplate 10. The surgical tool 40 is used to position and rotate the sizingplate 10 in the valve annulus such that the size and shape of the valveannulus can be accurately assessed under standard visualizationtechniques. The surgical tool 40 facilitates external manipulation ofthe sizing plate in the valve annulus. If the sizing plate 10 is toosmall or too large when compared to the valve annulus, the sizing plate10 can be retrieved and removed from the patient's body. In oneembodiment, the suture threaded through the aperture 16 provided in thesizing plate 10 is used to remove the sizing plate from the patient'sbody. A sizing plate 10 of a smaller or larger size is then selected,and the process is repeated until the size of the valve annulus isdetermined. Once the size of the valve annulus has been determined, thesurgeon can proceed with repairing or replacing the valve.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the above described features.

1. A sizing plate for sizing a native valve annulus in a patient's heartduring a minimally invasive mitral valve replacement or repairprocedure, the sizing plate comprising: an upper surface and a lowersurface defining a thickness of the sizing plate between the upper andlower surfaces; first and second keyways extending through the sizingplate from the upper planar surface to the lower planar surface of thesizing plate; and a bridge member between the first and second keywaysconfigured to be engaged by a laparascopic grasping tool.
 2. The sizingplate according to claim 1, wherein the sizing plate is generallyD-shaped.
 3. The sizing plate according to claim 1, wherein the sizingplate has a shape generally corresponding to a shape of an anteriorleaflet of a native mitral valve.
 4. The sizing plate according to claim1, wherein the bridge member comprises a bar coupled to the sizingplate.
 5. The sizing plate according to claim 1, wherein at least aportion of the sizing plate is radiopaque.
 6. The sizing plate accordingto claim 1, wherein the first and second keyways have a trapezoidalshape.
 7. The sizing plate according to claim 1, wherein the sizingplate is generally D-shaped having a major dimension and a minordimension, and wherein the bridge is oriented substantially parallel tothe major dimension.
 8. The sizing plate according to claim 1, furthercomprising an aperture extending through the upper and lower surfacesdisposed near a lower edge of the sizing plate.
 9. The sizing plateaccording to claim 1, wherein the thickness of the sizing plate definedbetween the upper planar surface and the lower planar surface is suchthat the sizing plate is adapted to be inserted through a space betweena patient's ribs when the sizing plate is oriented on an edge.
 10. A kitfor sizing a native valve annulus in a patient's heart during aminimally invasive mitral valve replacement or repair procedure, the kitcomprising: a plurality of sizing plates of differing size for sizingthe native valve annulus, each sizing plate having a shape generallycorresponding to a shape of an anterior leaflet of the native mitralvalve and having a major dimension and a minor dimension, wherein atleast one of the major dimension and the minor dimension varies amongthe plurality of sizing plates, each sizing plate further including: anupper planar surface and a lower planar surface defining a thickness ofthe sizing plate between the upper and lower planar surfaces; first andsecond keyways extending through the sizing plate from the upper planarsurface to the lower planar surface of the sizing plate; and a bridgebetween the first and second keyways configured to be engaged by alaprascopic grasping tool.
 11. The kit according to claim 10, whereinthe bridge of each sizing plate is oriented substantially parallel tothe major dimension.
 12. The kit according to claim 10, furthercomprising a grasping tool.
 13. The kit according to claim 10, whereineach sizing plate is generally D-shaped.
 14. The kit according to claim10, wherein the first and second keyways of each sizing plate have atrapezoidal shape.
 15. The kit according to claim 10, wherein each ofthe sizing plates further comprises at least one aperture disposed neara lower edge of the sizing plate.
 16. The kit according to claim 10,wherein the thickness of each of the sizing plates is such that thesizing plate is adapted to be inserted through a space between apatient's ribs when the sizing plate is oriented on an edge.
 17. Amethod of sizing a native valve annulus during a minimally invasivemitral valve repair or replacement procedure comprising: a) creating asurgical access port in an intercostals space in a patient's body; b)exposing the native valve annulus; c) inserting a first sizing platethrough the surgical access port, the first sizing plate including: anupper surface and a lower surface defining a thickness of the sizingplate; first and second keyways extending through the sizing plate fromthe upper planar surface to the lower planar surface of the sizingplate; and a bridge member between the first and second keywaysconfigured to be engaged by a laparoscopic grasping tool; d) engagingthe bridge of the sizing plate using a laparoscopic grasping toolinserted through the surgical access port; e) positioning the sizingplate in the valve annulus; f) comparing the major and minor dimensionsand the shape of the sizing plate to a major and a minor dimension andshape of an anterior leaflet of the mitral valve; and g) determining themajor and minor dimensions and shape of the anterior leaflet of themitral valve.
 18. The method according to claim 17, further comprisingthe steps of: removing the first sizing plate from the patient's body;inserting a second sizing plate through the surgical access port, thesecond sizing plate comprising a major dimension and a minor dimensionand a shape generally corresponding to the shape of an anterior leafletof the native mitral valve; an upper planar surface and a lower planarsurface defining a thickness of the sizing plate; and a first keyway anda second keyway to facilitate engagement of a grasping tool with thesizing plate, the first and second keyways generally centered on thesizing plate and extending through the sizing plate from the upperplanar surface to the lower planar surface of the sizing plate; andrepeating steps c)-g).
 19. The method according to claim 17, furthercomprising the step of temporarily suspending the first sizing platethrough the access port.
 20. The method according to claim 17, furthercomprising the step of orienting the first sizing plate on an edge wheninserting the first sizing plate through the surgical access port.